5
Giza Governorate
1 Choose the correct answer from the given ones:
Awseem Educational Directorate
Mathematics Inspection
(1) If B is a row matrix and if: \( \mathrm{b}_{x_{y}}=6 \), then \( 3 x= \)
(a) 6
(b) 3
(2) If \( \mathrm{A}=\left(\begin{array}{rr}2 & -3 \\ -1 & 4\end{array}\right), \mathrm{B}=\left(\begin{array}{rr}2 \mathrm{k} & -1 \\ 3 \mathrm{~m} & 4\end{array}\right) \) where \( \mathrm{A}=\mathrm{B}^{\text {t }} \), then \( 2 \mathrm{k}+3 \mathrm{~m}= \)
(d) \( 6 x \)
(a) 1
(b) -1
(c) 2
\( 2+-3= \)
(d) 3
(3) If the matrix \( \left(\begin{array}{lr}6 & 2 \\ x-2 & -4\end{array}\right) \) has no multiplicative inverse, then \( x= \) \( \qquad \)
(a) -10
(b) -8
(c) 8
(d) 10
(4) The possible value of \( k \) which makes the determinant \( \left|\begin{array}{rrr}1 & 2 & -1 \\ 3 & k & 1 \\ -1 & 4 & -2\end{array}\right|=0 \) is \( \qquad \)
(a) 5
(b) -2
(c) 1
(d) 3
(5) The surface area of the triangle whose vertices are \( \mathrm{A}(2,4), \mathrm{B}(-2,4) \) , C \( (0,-2) \) equals \( \qquad \) square unit.
(a) 24
(b) 12
(c) 6
(d) 22
(6) If \( \left(\begin{array}{rr}6 & 1 \\ 5 & -3\end{array}\right)=x\left(\begin{array}{ll}0 & 1 \\ 5 & 0\end{array}\right)+y\left(\begin{array}{cc}-2 & 0 \\ 0 & 1\end{array}\right) \), then \( 2 x+y= \) \( \qquad \)
(c) 2
(d) 6
(b) -1
(a) 1